Oil an oven dish and arrange some sliced onion on the bottom. Add a layer of zucchini, potatoes and peppers combined and top with part of the tomato mixture. Season with salt and pepper to taste, sprinkle on some of the herbs and oil. Repeat until all ingredients are used, about 3 to 4 layers depending on the size of the dish, finish with herbs and oil.

Cover and put in a preheated 350 F. oven for 90 minutes, until vegetables become tender. Remove cover for the last 15 minutes.